(Visibility of Frames): Mention the effect multiple

workspaces/desktops can have on visibility.

(as I learnt in bug#2199).

doc/lispref/ChangeLog

+2009-02-11  Glenn Morris  <rgm@gnu.org>
+
+	* frames.texi (Visibility of Frames): Mention the effect multiple
+	workspaces/desktops can have on visibility.
+
 2009-02-07  Eli Zaretskii  <eliz@gnu.org>
 
-	* text.texi (Commands for Insertion): 
-	* commands.texi (Event Mod): 
-	* keymaps.texi (Searching Keymaps): 
+	* text.texi (Commands for Insertion):
+	* commands.texi (Event Mod):
+	* keymaps.texi (Searching Keymaps):
 	* nonascii.texi (Translation of Characters): Reinstate
 	documentation of translation-table-for-input.
 	(Explicit Encoding): Document the `charset' text property produced

doc/lispref/frames.texi

@@ -1416,8 +1416,11 @@ position consistent with the new selected frame.
 A window frame may be @dfn{visible}, @dfn{invisible}, or
 @dfn{iconified}.  If it is visible, you can see its contents, unless
 other windows cover it.  If it is iconified, the frame's contents do
-not appear on the screen, but an icon does.  If the frame is
-invisible, it doesn't show on the screen, not even as an icon.
+not appear on the screen, but an icon does.  (Note: because of the
+way in which some window managers implement the concept of multiple
+workspaces, or desktops, all frames on other workspaces may appear to
+Emacs to be iconified.)  If the frame is invisible, it doesn't show on
+the screen, not even as an icon.
 
 Visibility is meaningless for terminal frames, since only the selected
 one is actually displayed in any case.